ok recently my car has been lacking power and when i got on it it made a whistling noise. So i look under the hood and see that the intake manifold is leaking coolant on the front drivers side . Should the leaking intake manifold cause loss of power and a whistling noise or is something else wrong with is also ??

 

If it's leaking coolant there's a good chance it's got a vacuum leak somewhere else too. The intake might be warped or cracked.

Then again, it could just be your thermostat housing. I can't see it so I don't know.